1. Field of the Invention
The present invention relates to a novel polyorganosiloxane compound suitable for modifying synthetic resins.
2. Description of Related Art
Heretofore, silicone resins have been employed for providing synthetic resin molded products with various characteristics such as surface properties including water repellency, mold releasability and antifouling properties inherent in siloxane compounds as well as thermal resistance. These silicone resins are mainly composed of linear polysiloxane compounds. The linear polysiloxane compounds are blended if they do not possess a group or groups reactive with the resins while they are chemically introduced into the resins if they possess a group or groups reactive therewith.
Increasing attention has recently been paid to polysiloxane compounds for use as raw materials of graft polymers for modifying synthetic resins. As such polysiloxane compounds have been mainly employed so-called "polysiloxane compounds modified at one terminal" in which a reactive group resides at only one of their terminals and a trimethylsiloxy group resides at the other terminal.
When the polysiloxane compounds are used with the attempt to improve characteristics of synthetic resins, improvements in characteristics of the synthetic resins rely primarily upon functions inherent in the polysiloxane compounds in order to satisfy recent demands for higher functional characteristics. Therefore, it poses the difficulties that insufficient improvements have been achieved or a large quantity of the polysiloxanes should be added to achieve characteristics sought to be performed by addition, thereby adversely affecting other characteristics.
When there is used a polysiloxane compound wherein its both terminals are provided with the same substituents i.e., a so-called "polysiloxane compound modified at both terminals", which are not reactive with the objective synthetic resin, it suffers the disadvantages that the amount of the polysiloxane compound to be added cannot be increased on account of bleeding and fluctuations in characteristics may occur to a remarkably large extent as time elapses, whereby the expected characteristics cannot be maintained for a long period of time.
On the contrary, when the polysiloxane modified at both terminals is used in which groups substituents reactive with the synthetic resins are used for their surface modifications, it also poses the difficulty that a large amount of the polysiloxane compound should be added, thereby resulting in a remarkable reduction in other properties. Furthermore, it is difficult to use the polysiloxane compound modified at both terminals as a graft polymer which has recently drawn increasing attention for modifying surfaces of the synthetic resins.
In the polysiloxane compound modified at its one terminal, a group at its one terminal which is not reactive with the synthetic resins is generally constituted a trimethylsiloxy group, and modifications of characteristics for the synthetic resins are dependent upon the properties of the polysiloxane compound. Therefore, demands for higher functions are not achieved to a sufficient extent or a large amount of the polysiloxane compound should be added in order to satisfy the characteristics sought to be attained, thus adversely affecting other properties.
It is further to be noted that dimethylsiloxane alone, in which its terminal is terminated by means of the trimethylsiloxy group, can little improve an oil repellency.